1. Field of the Invention
The present invention relates to a collapsible, four-legged walker aid apparatus for those persons requiring walkers to travel on either level or inclined ground, and to negotiate stairs. The stair walker has four extendable and retractable vertical legs, with each of the front two legs being made up of three concentric tubes controllable by individual hand control levers and cables, to extend or retract the front pair of legs simultaneously.
2. Description of Related Art
References
The related art of interest shows various stair walkers and mechanisms for extending and retracting walker appendages. The related art will be discussed in the order of perceived relevance to the present invention.
U.S. Pat. No. 5,649,558 issued on Jul. 22, 1997, to Reginald L. Richards describes an accommodation walker having four legs with shortening of the front pair of legs occurring by separate hand controls to manipulate an externally exposed rack and gear control through exposed cables. The front legs are lengthened only by gravity when the racks and gears are disengaged. A reversible motor may be substituted for the rack and gears mechanism. The rear legs may be shortened by spring loaded push buttons (not shown) that cooperate with extension holes. The walker is distinguishable by its reliance on separate hand controls for the front pair of extendable legs for shortening by the non-equivalent exposed cables, rack and gear controls and motor, i.e., both handles are necessary. The front legs are lengthened manually with the aid of gravity. The present invention hides the cables and spring mechanism by the use of three tubes. Additionally, there is no suggestion for folding the walker in the manner taught in the present invention.
U.S. Pat. No. 3,455,313 issued on Jul. 15, 1969, to Harold L. King describes a four-legged walker with two arcuate cross braces. Each leg has an overlapping apertured leg extension mechanism that is extendable by a spring which is released by a right and left hand grip housing two pins traveling in slots in either the pipe or the handgrip. A cable from the hand-grip retracts a semicircular spring connected pin from a hole in the overlapping leg extension. A second coil spring effects the extension of a leg until the pin enters another hole to lock the leg extension. The separate hand-grip mechanisms and the pin locking mechanism are totally different from the single hand possible locking mechanism of the present invention. Additionally, the walker has external legs as opposed to the internal legs of the present invention and is not foldable.
U.S. Pat. No. 3,176,700 issued on Apr. 6, 1966, to John H. Drury, Jr. describes a walking aid device consisting of a tubular frame with four legs, and upper arcuate front bar, a U-shaped support bar, and hand grips on the sides of the upper arcuate front bars. The two legs regarded as rear legs have contractible leg portions which telescope into the fixed legs by depressing locking buttons located at the mid-sections of the rear legs and contracting coiled springs. Each adjustable leg is locked in a shortened state by the button accessing another hole in the upper leg. The locking button is motivated by another U-shaped spring. A bolt in an upper leg travels in a slot of the contracting leg to maintain a non-twisting condition. The process of ascending and descending stairs requires the user to rotate the walker 180 degrees. The walker is distinguishable by having only two adjustable legs, a non-folding walker and the requirement for laboriously reaching down for the release button on each leg.
U.S. Pat. No. 4,411,283 issued on Oct. 25, 1983, to Frank J. Lacarelli describes an invalid walker formed from tubular aluminum having a telescoping front leg assembly which slides through a pair of guide tubes and is integrated with a cross bar adjustment member. The rear pair of legs have hand grips on an upper medial and integral front support and an additional lower support frame, wherein both supports are clamped to the front guide tubes. The front legs are adjustable in a height range of 2 feet by utilizing a manually movable locking assembly with a clip on each leg which slides into one of 24 slots in the inner surface of the front legs. The lock must be removed first before the clip can be moved along the telescoping leg. A click and drag pin is also located on an inner surface of the guide tube to indicate the movement of the telescoping legs. The rear legs have adjustable foot portions with indexing buttons and elongated feet directed inward. The walker is distinguished by individual locking of only two front legs clips which must be manipulated by hand in a two-step process. Also, the front legs lack springs to motivate either the extension or retraction of the legs.
U.S. Pat. No. 5,636,651 issued on Jun. 10, 1997, to Eli Einbinder describes an adjustably controllable walker with two U-shaped tubes with a cross bar and four legs with wheels which can be controlled by an actuator means such as a button, pressure sensor or lever. The actuator may control a stabilizer brake mechanism to engage or release a brake. Lifting the walker can release the brake. A strain gauge or lifters may be provided to respond to the lifting force. The walker is distinguishable by its reliance on wheels and brake mechanisms.
U.S. Pat. No. 2,708,473 issued on May 17, 1955, to Harry L. Gable et al. describes a walker with six legs and feet, wherein the middle legs are positioned by set screws acting through collars on upper side bracing members. Anther set of collars on lower side bracing members stabilize the middle pair of extendable legs. The walker is deemed distinguishable by its requirement for six legs and manual adjustment of each middle leg in negotiating a flight of steps.
U.S. Pat. No. 3,387,618 issued on Jun. 11, 1968, to David T. Swann describes a walker in the form of a cane or a crutch on a vertical shaft welded to a horizontal yoke member with a pair of pivotal and vertical short legs extendable from a braced upper sleeve portion. The vertical shaft has a pivotal horizontal upper leg with a cross arm which is extendable from a sleeve section. The configuration of the walker thus accommodates three steps. The walker is distinguishable by its three-step stair conforming structure.
U.S. Pat. No. 3,421,529 issued on Jan. 14, 1969, to Richard A Vestal describes another three-step stairway walker having a main frame formed from an upper horizontal U-shaped member secured at its middle front portion, and two rectangular and vertical side subframes. Each vertical side subframe has a set of L-shaped leg portions with shorter rear leg portions. The outwardly extending feet are attached vertically to the main frame by a plurality of sleeves with the uppermost sleeve having thumb screws for securing the legs by the user. The front and rear sets of feet are adjusted to conform to the steps. The walker is distinguishable by its three-step structure.
U.S. Pat. No. 4,094,331 issued on Jun. 13, 1978, to Peter Rozsa describes a walker for negotiating stairs by ascending in one position and descending by reversing the position of the walker, and walking on a level surface by inverting the walker. The walker consists of two side frames substantially in the form of a rectangle with an indented top portion having a centered rubber or plastic sleeve. A necked and coupled center portion has a leg extending on each side (front or rear) and a pair of handles extending from a region above the necked portion and directly above the extended legs. The extendable legs are apertured sleeves locked by a spring loaded pin. The walker is distinguishable by its reliance on extending only two legs manually instead of automatically.
U.S. Pat. No. 5,740,825 issued on Apr. 21, 1998, to P. J. Brunengo describes an articulated walker having a first and second side section, each having a front and rear leg, an upper cross section, and a lower cross section. The side sections are coupled by an upper horizontal cross bar and a lower horizontal cross bar. The walker adjusts for stair height by a pivotal relationship between the upper and lower cross ties and the front and rear legs. Adjustment of the legs is achieved by pulling on handles that release a pin-locked cam mechanism located on the lower cross tie of each side section. The walker is distinguishable by not having individual legs that are adjustable and not maintaining a level upper cross tie for gripping when ascending or descending stairs.
U.S. Pat. No. 5,349,977 issued on Sep. 27, 1994, to Maurice Wood describes a kit including four supplemental legs, two actuating bars, and the mechanical means to attach the apparatus to an existing walker for the accommodation of stairs or inclines. The user is able to adjust the front and back legs of one side of the walker by pulling the actuating lever and letting gravity adjust the legs to a desired height. This allows the user to navigate stairs by leaving the walker pointed straight ahead and engaging both actuator bars, or turning the walker sideways and engaging only one actuator bar. This inventions is distinguishable in that it is an attachment to an existing walker and therefore has external components, and also by the ability to control both legs on one side with the one actuator bar but not both front legs with one lever.
U.S. Pat. No. 5,603,517 issued on Feb. 18, 1997, to Shmil Lorman describes a rollable and foldable walker frame having a seat, four wheels, and four handles. The wheels can be locked automatically by braking devices. The walker frame comprises a first frame element consisting of two parallel curvilinear tubes with extendable curved handles at the upper ends, and non-extendable wheeled legs at the opposite ends which are connected by a cross bar. A second frame element which is U-shaped in front and with L-shaped sides comprises a foldable seat with non-extendable rear wheeled legs. A third frame element with two parallel inverted L-shaped tubular portions has a second set of height adjustable handles at its upper ends, and its opposite ends are connected to the pair of first frame elements. Two pairs of braking devices are connected to the rear and front legs, each of the braking devices slidably supports one of the wheel mounts over a wheel such that the application on the frame of a downward force urges the braking of the wheels. The walker is distinguishable by its unique braking devices and four wheels.
U.S. Pat. No. 4,995,412 issued on Feb. 26, 1991, to Doris Hirn et al, describes a walker with two side sections connected in the front by two horizontal cross bars. The device is able to be transformed into a cane and is also adjustable for people of varying height and width. The walker is distinguishable by needing manual adjustment for ascending or descending stairs.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The present invention relates to a foldable four-legged walker aid apparatus for those persons requiring walkers to travel on either level ground or inclined ground, and to negotiate both the ascent and descent of stairs. The stair walker has four extendable an retractable vertical legs, with the front two legs each being made up of three concentric tubes controllable by individual hand control levers and cables, to extend or retract the front pair of legs simultaneously. Each control lever controls both front legs, affording the advantage that a user with impaired use of one upper extremity may use just one hand to control both front legs.
Accordingly, it is a principal object of the invention to provide a four-legged walker aid apparatus with a pair of adjustable front legs and a pair of adjustable rear legs.
It is another object of the invention to provide a four-legged walker aid apparatus for traveling on either level ground, inclined ground, or in negotiating stairs.
It is a further objective of the invention to provide a four-legged walker aid apparatus wherein the pair of front legs can be automatically extended and retracted by hand control, and the height of the pair of rear legs can be adjusted manually.
Still another object of the invention is to provide a four-legged walker aid apparatus which is foldable for storage or for transporting the device, such as in a car or on escalator stairs.
Yet a further object of the invention is to provide a four-legged walker aid apparatus with one size which can accommodate persons of any height by adjustment of the P-shaped rear frame elements within the bracket holding each of the P-shaped rear frame elements to the front leg frame element.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purpose described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specifications and drawings.